Electronic systems and circuits are often utilized in a number of scenarios to achieve advantageous results. Numerous electronic technologies such as computers, video equipment, and communication systems facilitate increased productivity and cost reduction in analyzing and communicating information in most areas of business, science, education and entertainment. Frequently, these activities involve storage of vast amounts of information and significant resources are expended storing and processing the information. Maintaining accurate replicated backup storage of the information is often very important for a variety or reasons (e.g., disaster recovery, corruption correction, system maintenance, etc.).
Resource clusters are often relied upon to provide services and to store data. In general, there are different types of clusters, such as, for example, compute clusters, storage clusters, scalable clusters, and the like. High-availability clusters (also known as HA Clusters or Failover Clusters) are typically clusters of node resources (e.g., computers, networks, applications, virtual components, servers, data storage, etc.) that are implemented primarily for the purpose of providing high availability of services. They usually operate by having redundant components or nodes that can be utilized to provide service in various scenarios (e.g., when system components fail, a maintenance shutdown of a certain portion, minimizing single points of failure, etc.). The clusters can be utilized to minimize data loss and implement DR (disaster recovery) quickly. Periodic replication is one technique utilized to minimize data loss and improve the availability of data in which a point-in-time copy of data is replicated and stored at one or more remote sites or nodes.
Accurately duplicating the information in a consistent manner is typically very important. Some traditional backup approaches utilize snapshots or checkpoints in an attempt to allow Applications to continue to write to the primary file system while a backup is in progress without burdening the application making use of that file system. The storage checkpoints or file system snapshots are often utilized for ensuring a backup is taken of an image at a consistent point in time. Depending upon the amount of data to be processed from the snapshot, the lifetime of the snapshot can be quite long, especially if the backup/replication application requires a persistent snapshot during the entire backup process.
When “switching over” primary application execution to another resource, HA clustering usually attempts to provide “restart” or “continuation” of primary application operations on the other system without requiring administrative intervention (e.g., a process known as Failover, etc.). In preparation to be ready for a switch over, clustering software typically configures the potential redundant switch over target nodes before starting primary application operations on the target node resources. For example, appropriate file systems may need to be imported and mounted, network hardware may have to be configured, and some supporting applications may need to be running as well.